a. Field of the Invention
The instant disclosure relates generally to catheters for use in the human body. More specifically, the disclosure relates to a catheter handle that reduces the risk of the failure of such catheters when subjected to torques.
b. Background Art
Catheters are used for an ever growing number of medical procedures. To name just a few examples, catheters are used for diagnostic, therapeutic, and ablative procedures. Typically, the physician manipulates the catheter through the patient's vasculature to the intended site, such as a site within the patient's heart. The catheter typically carries one or more electrodes or other diagnostic or therapeutic devices, which can be used for ablation, diagnosis, cardiac mapping, or the like.
Since the path a catheter must navigate within a patient is often long and tortuous, steering forces must be transmitted over relatively great distances. It is known, however, to utilize one or more pull wires, which are typically offset from the central longitudinal axis of the catheter and which can be attached to one or more pull rings proximate the distal end of the catheter shaft, to manipulate the distal end of the catheter. Often, these pull wires are embedded into the wall of the catheter (as opposed to, for example, routed through a lumen within the interior of the catheter).
It is also desirable for the catheter to transmit a torque applied at the proximal end to the distal end. It has been discovered, however, that the amount of torque that can be applied to a catheter is limited, particularly where the pull wires are embedded in the catheter wall. For example, if the catheter shaft has a strong bend in it and is also deflected (e.g., one or more of the embedded pull wires is under tension), it will be difficult to impart a torque to the catheter shaft. If an operator applies additional torque to the catheter handle in an effort to overcome this “lockup” in the shaft, there is a risk of catheter failure.